Process for making magneto rotors



Feb. 12, 1935. J. BOHLI 1,991,046

PROCESS FOR MAKING MAGNETO ROTORS Filed June 16, 1933 Patented Feb.12, 1935 UNITED STATES PATENT OFFICE PROCESS FOR MAKING MAGNETO ROTORS Jakob Bohli, Solothurn, Switzerland Application June 16, 1933, Serial No. 676,153

. Germany June 23, 1932 1 Claim.

The subject of the present invention relates to a process of making magneto rotors. Such rotors are fitted out with bundles of sheet iron for preventing eddy-currents.

According to the present invention the sheets are mounted to the parts of the electric machines which are to be fitted out therewith, and cast into non-magnetic material, thereby being firmly pressed against the parts of the machine after cooling off of this non-magnetic material. 0n the drawing a constructional form of the subject of ,this invention is shown, particularly a pole wheel of a magnetic electric machine.

Fig. 1 is a plan view of a pole wheel.

Fig. 2 is a plan view of the laminated sheet iron.

Fig. 3 is a sectional view of the unit obtained by casting elements of Figs. 1 and 2 together and turning down the periphery.

Fig. 4 is a section on line CD of Fig. 3.

Fig. 5 is a sectional view of the unit obtained by casting elements of Figs. 1 and 2 together and before the periphery of the sheet iron has been turned down.

In the figures a represents the pole wheel with the bundle of sheet iron b. c is the non-magnetic material by means of which the sheets b are firmly fixed to the arms 'of the pole wheel. The process consists now generally speaking in that 80 the sheets I) are mounted on the parts, of the electric machines which are to be fitted out therewith and then cast into a non-magnetic material which may be non-magnetic metal or insulating material. In cooling off, this nonmagnetic material contracts and binds the sheets firmly on to the parts of the machine. In the case of a pole wheel the sheets are punched out according to Fig. 2 as a continuous ring which is 5 mounted on the pole wheel and then cast into non-magnetic material. This stage of the process is shown in Fig. 6. These rings are turned down in such a way that the laminated sheets on the outside of the pole wheel are no longer 10 connected to one another by metal pieces conducting the magnetic flux. The laminated pole wheel has finally the form as shown by the Figures 3 and 4.

What I claim is:

The process of building a magneto rotor which consists of forming annular, continuous ring laminations having regularly spaced, inwardly extending projections on their internal peripheries, assembling said laminations in stacked 20 formation with their projections in registry and in radial abutting relation to the corresponding polar projections of a pole wheel, uniting the parts thus assembled, by the use of non-magnetic casting material, into an homogeneous, integral :5 rotor wheel, whose parts are held in rigid, intimate assembly by the contraction, due to cool- 7 ing, of the said material, and turning down the external periphery an amount sufllcient to disconnect, magnetically, the spaced, inwardly exso tending projections of the original ring laminations.

JAKOB BOHLI. 

